A like control device is known as EP 0 175 089 B1, wherein an inertia member serves to control a switch valve which is interposed between a brake fluid tank and a chamber confined by a control piston. The switch valve is designed as a tilting valve which is kept open by the inertial member until a determined declaration is reached and the spherical inertial member ascends a ramp to permit the tilting valve to close. The chamber is shut off starting from this point of time, and further displacement of the control piston into the chamber it confines is not possible so that, after further rise of the master cylinder pressure, the regulating piston can be brought into sealing engagement with the valve closure member.
The mentioned state of the art entails several shortcomings. On the one hand, the hydraulic locking of the control piston by a closable chamber involves great structural forces. On the other hand, the movement of the inertial member is viscosity-responsive and hence temperature-responsive, in addition thereto the ball-ramp arrangement does not provide the necessary, very short on/off time of the switch valve.